2151791 has 2 divisors, whose sum is σ = 2151792. Its totient is φ = 2151790.

The previous prime is 2151781. The next prime is 2151817. The reversal of 2151791 is 1971512.

It is an a-pointer prime, because the next prime (2151817) can be obtained adding 2151791 to its sum of digits (26).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2151791 - 2¹⁴ = 2135407 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2151791.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2151701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1075895 + 1075896.

It is an arithmetic number, because the mean of its divisors is an integer number (1075896).

2^2151791 is an apocalyptic number.

2151791 is a deficient number, since it is larger than the sum of its proper divisors (1).

2151791 is an equidigital number, since it uses as much as digits as its factorization.

2151791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 630, while the sum is 26.

The square root of 2151791 is about 1466.8984286582. The cubic root of 2151791 is about 129.1021165271.

The spelling of 2151791 in words is "two million, one hundred fifty-one thousand, seven hundred ninety-one".